package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @author 王艺锡
 * @version 1.0
 */
@Component
public class RedisIdWorker {
    /**
     * 开始时间戳
     */
    private static final long BEGIN_TIMESTAMP = 1704067200L;
    /**
     * 序列号的位数
     */
    private static final long COUNT_BITS = 32;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    public long nextId(String keyPrefix){
        //1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        //求出时间戳
        long timestamp = nowSecond - BEGIN_TIMESTAMP;
        //2.生成序列号
        //获取当前日期，精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        //3.拼接

        return timestamp << COUNT_BITS | count;
    }

}
